1. Field of the Invention
The present invention relates to interconnected locks, i.e., locks in which the outside of the door has a latchbolt lock mechanism on the bottom and a separate deadbolt lock mechanism on the top, but on the inside the mechanisms are interconnected so that rotating the inner handle automatically retracts both the latchbolt and the deadbolt, without having to separately unlock the two.
2. Description of Related Art
Many local codes dictate when a deadbolt is in use the lockset must be an interconnected type lockset to allow simultaneous retraction of both the latchbolt and the deadbolt during egress from the inside of the door, i.e., the inside of the house or apartment, or the side of the door for which security is otherwise desired. Existing interconnect products have a fixed center to center distance measured from the center of rotation of the lever handle, where the latchbolt is positioned, to the centerline of the deadbolt. This fixed dimension of latchbolt/deadbolt axis spacing, or offset distance, is typically either 4 in. (102 mm) or 5.5 in. (140 mm) center to center. For new construction projects consumers can specify door preparation so the offset center-to center distance is not so much of an issue. There is a benefit to offering an adjustable interconnected lock for consumers on renovation and retro fit projects where the door is usually not replaced. There is typically a mix in the market place of 4 in. (102 mm) and 5.5 in. (140 mm) door preparations, but in interconnect markets the predominant door preparation is 4 in. (102 mm) as most competitive interconnects are 4 in. (102 mm). In non-interconnect markets the 5.5 in. (140 mm) distance is often used with a deadbolt and passage. The biggest driver for covering both preparations is to comply with the International Building Code (IBC). As more states adopt the IBC interconnected locks will increase in use as single handle motion egress is required. The ability to retrofit both offset distances without re-prepping or buying new doors would be advantageous.
An existing system for accommodating both 4 in. (102 mm) and 5.5 in. (140 mm) latchbolt-deadbolt offset spacing is disclosed in U.S. Pat. No. 8,434,335. However, this system requires the installer to partially disassemble the interior components of the door latch and deadbolt assembly to remove or add an insert slide when switching between the 4 in. (102 mm) and 5.5 in. (140 mm) latchbolt/deadbolt offset spacing. It would be advantageous to be able to switch between different latchbolt-deadbolt offset spacings without any disassembly of the assembly that operates the deadbolt, either partially or completely, and without adding or removing any components thereof. This would eliminate the potential of losing parts during the spacing adjustment. It would also be advantageous to accomplish the switch between different latchbolt/deadbolt spacings without the need for using any tools, which would simplify such changeover.